/**
 * @author mrdoob / http://mrdoob.com/
 */
export function OBJLoader(THREE) { 
	THREE.OBJLoader = ( function () {
	
		// o object_name | g group_name
		var object_pattern = /^[og]\s*(.+)?/;
		// mtllib file_reference
		var material_library_pattern = /^mtllib /;
		// usemtl material_name
		var material_use_pattern = /^usemtl /;
	
		function ParserState() {
	
			var state = {
				objects: [],
				object: {},
	
				vertices: [],
				normals: [],
				colors: [],
				uvs: [],
	
				materialLibraries: [],
	
				startObject: function ( name, fromDeclaration ) {
	
					// If the current object (initial from reset) is not from a g/o declaration in the parsed
					// file. We need to use it for the first parsed g/o to keep things in sync.
					if ( this.object && this.object.fromDeclaration === false ) {
	
						this.object.name = name;
						this.object.fromDeclaration = ( fromDeclaration !== false );
						return;
	
					}
	
					var previousMaterial = ( this.object && typeof this.object.currentMaterial === 'function' ? this.object.currentMaterial() : undefined );
	
					if ( this.object && typeof this.object._finalize === 'function' ) {
	
						this.object._finalize( true );
	
					}
	
					this.object = {
						name: name || '',
						fromDeclaration: ( fromDeclaration !== false ),
	
						geometry: {
							vertices: [],
							normals: [],
							colors: [],
							uvs: []
						},
						materials: [],
						smooth: true,
	
						startMaterial: function ( name, libraries ) {
	
							var previous = this._finalize( false );
	
							// New usemtl declaration overwrites an inherited material, except if faces were declared
							// after the material, then it must be preserved for proper MultiMaterial continuation.
							if ( previous && ( previous.inherited || previous.groupCount <= 0 ) ) {
	
								this.materials.splice( previous.index, 1 );
	
							}
	
							var material = {
								index: this.materials.length,
								name: name || '',
								mtllib: ( Array.isArray( libraries ) && libraries.length > 0 ? libraries[ libraries.length - 1 ] : '' ),
								smooth: ( previous !== undefined ? previous.smooth : this.smooth ),
								groupStart: ( previous !== undefined ? previous.groupEnd : 0 ),
								groupEnd: - 1,
								groupCount: - 1,
								inherited: false,
	
								clone: function ( index ) {
	
									var cloned = {
										index: ( typeof index === 'number' ? index : this.index ),
										name: this.name,
										mtllib: this.mtllib,
										smooth: this.smooth,
										groupStart: 0,
										groupEnd: - 1,
										groupCount: - 1,
										inherited: false
									};
									cloned.clone = this.clone.bind( cloned );
									return cloned;
	
								}
							};
	
							this.materials.push( material );
	
							return material;
	
						},
	
						currentMaterial: function () {
	
							if ( this.materials.length > 0 ) {
	
								return this.materials[ this.materials.length - 1 ];
	
							}
	
							return undefined;
	
						},
	
						_finalize: function ( end ) {
	
							var lastMultiMaterial = this.currentMaterial();
							if ( lastMultiMaterial && lastMultiMaterial.groupEnd === - 1 ) {
	
								lastMultiMaterial.groupEnd = this.geometry.vertices.length / 3;
								lastMultiMaterial.groupCount = lastMultiMaterial.groupEnd - lastMultiMaterial.groupStart;
								lastMultiMaterial.inherited = false;
	
							}
	
							// Ignore objects tail materials if no face declarations followed them before a new o/g started.
							if ( end && this.materials.length > 1 ) {
	
								for ( var mi = this.materials.length - 1; mi >= 0; mi -- ) {
	
									if ( this.materials[ mi ].groupCount <= 0 ) {
	
										this.materials.splice( mi, 1 );
	
									}
	
								}
	
							}
	
							// Guarantee at least one empty material, this makes the creation later more straight forward.
							if ( end && this.materials.length === 0 ) {
	
								this.materials.push( {
									name: '',
									smooth: this.smooth
								} );
	
							}
	
							return lastMultiMaterial;
	
						}
					};
	
					// Inherit previous objects material.
					// Spec tells us that a declared material must be set to all objects until a new material is declared.
					// If a usemtl declaration is encountered while this new object is being parsed, it will
					// overwrite the inherited material. Exception being that there was already face declarations
					// to the inherited material, then it will be preserved for proper MultiMaterial continuation.
	
					if ( previousMaterial && previousMaterial.name && typeof previousMaterial.clone === 'function' ) {
	
						var declared = previousMaterial.clone( 0 );
						declared.inherited = true;
						this.object.materials.push( declared );
	
					}
	
					this.objects.push( this.object );
	
				},
	
				finalize: function () {
	
					if ( this.object && typeof this.object._finalize === 'function' ) {
	
						this.object._finalize( true );
	
					}
	
				},
	
				parseVertexIndex: function ( value, len ) {
	
					var index = parseInt( value, 10 );
					return ( index >= 0 ? index - 1 : index + len / 3 ) * 3;
	
				},
	
				parseNormalIndex: function ( value, len ) {
	
					var index = parseInt( value, 10 );
					return ( index >= 0 ? index - 1 : index + len / 3 ) * 3;
	
				},
	
				parseUVIndex: function ( value, len ) {
	
					var index = parseInt( value, 10 );
					return ( index >= 0 ? index - 1 : index + len / 2 ) * 2;
	
				},
	
				addVertex: function ( a, b, c ) {
	
					var src = this.vertices;
					var dst = this.object.geometry.vertices;
	
					dst.push( src[ a + 0 ], src[ a + 1 ], src[ a + 2 ] );
					dst.push( src[ b + 0 ], src[ b + 1 ], src[ b + 2 ] );
					dst.push( src[ c + 0 ], src[ c + 1 ], src[ c + 2 ] );
	
				},
	
				addVertexPoint: function ( a ) {
	
					var src = this.vertices;
					var dst = this.object.geometry.vertices;
	
					dst.push( src[ a + 0 ], src[ a + 1 ], src[ a + 2 ] );
	
				},
	
				addVertexLine: function ( a ) {
	
					var src = this.vertices;
					var dst = this.object.geometry.vertices;
	
					dst.push( src[ a + 0 ], src[ a + 1 ], src[ a + 2 ] );
	
				},
	
				addNormal: function ( a, b, c ) {
	
					var src = this.normals;
					var dst = this.object.geometry.normals;
	
					dst.push( src[ a + 0 ], src[ a + 1 ], src[ a + 2 ] );
					dst.push( src[ b + 0 ], src[ b + 1 ], src[ b + 2 ] );
					dst.push( src[ c + 0 ], src[ c + 1 ], src[ c + 2 ] );
	
				},
	
				addColor: function ( a, b, c ) {
	
					var src = this.colors;
					var dst = this.object.geometry.colors;
	
					dst.push( src[ a + 0 ], src[ a + 1 ], src[ a + 2 ] );
					dst.push( src[ b + 0 ], src[ b + 1 ], src[ b + 2 ] );
					dst.push( src[ c + 0 ], src[ c + 1 ], src[ c + 2 ] );
	
				},
	
				addUV: function ( a, b, c ) {
	
					var src = this.uvs;
					var dst = this.object.geometry.uvs;
	
					dst.push( src[ a + 0 ], src[ a + 1 ] );
					dst.push( src[ b + 0 ], src[ b + 1 ] );
					dst.push( src[ c + 0 ], src[ c + 1 ] );
	
				},
	
				addUVLine: function ( a ) {
	
					var src = this.uvs;
					var dst = this.object.geometry.uvs;
	
					dst.push( src[ a + 0 ], src[ a + 1 ] );
	
				},
	
				addFace: function ( a, b, c, ua, ub, uc, na, nb, nc ) {
	
					var vLen = this.vertices.length;
	
					var ia = this.parseVertexIndex( a, vLen );
					var ib = this.parseVertexIndex( b, vLen );
					var ic = this.parseVertexIndex( c, vLen );
	
					this.addVertex( ia, ib, ic );
	
					if ( ua !== undefined && ua !== '' ) {
	
						var uvLen = this.uvs.length;
						ia = this.parseUVIndex( ua, uvLen );
						ib = this.parseUVIndex( ub, uvLen );
						ic = this.parseUVIndex( uc, uvLen );
						this.addUV( ia, ib, ic );
	
					}
	
					if ( na !== undefined && na !== '' ) {
	
						// Normals are many times the same. If so, skip function call and parseInt.
						var nLen = this.normals.length;
						ia = this.parseNormalIndex( na, nLen );
	
						ib = na === nb ? ia : this.parseNormalIndex( nb, nLen );
						ic = na === nc ? ia : this.parseNormalIndex( nc, nLen );
	
						this.addNormal( ia, ib, ic );
	
					}
	
					if ( this.colors.length > 0 ) {
	
						this.addColor( ia, ib, ic );
	
					}
	
				},
	
				addPointGeometry: function ( vertices ) {
	
					this.object.geometry.type = 'Points';
	
					var vLen = this.vertices.length;
	
					for ( var vi = 0, l = vertices.length; vi < l; vi ++ ) {
	
						this.addVertexPoint( this.parseVertexIndex( vertices[ vi ], vLen ) );
	
					}
	
				},
	
				addLineGeometry: function ( vertices, uvs ) {
	
					this.object.geometry.type = 'Line';
	
					var vLen = this.vertices.length;
					var uvLen = this.uvs.length;
	
					for ( var vi = 0, l = vertices.length; vi < l; vi ++ ) {
	
						this.addVertexLine( this.parseVertexIndex( vertices[ vi ], vLen ) );
	
					}
	
					for ( var uvi = 0, l = uvs.length; uvi < l; uvi ++ ) {
	
						this.addUVLine( this.parseUVIndex( uvs[ uvi ], uvLen ) );
	
					}
	
				}
	
			};
	
			state.startObject( '', false );
	
			return state;
	
		}
	
		//
	
		function OBJLoader( manager ) {
	
			this.manager = ( manager !== undefined ) ? manager : THREE.DefaultLoadingManager;
	
			this.materials = null;
	
		}
	
		OBJLoader.prototype = {
	
			constructor: OBJLoader,
	
			load: function ( url, onLoad, onProgress, onError ) {
	
				var scope = this;
	
				var loader = new THREE.FileLoader( scope.manager );
				loader.setPath( this.path );
				loader.load( url, function ( text ) {
	
					onLoad( scope.parse( text ) );
	
				}, onProgress, onError );
	
			},
	
			setPath: function ( value ) {
	
				this.path = value;
	
				return this;
	
			},
	
			setMaterials: function ( materials ) {
	
				this.materials = materials;
	
				return this;
	
			},
	
			parse: function ( text ) {
	
				console.time( 'OBJLoader' );
	
				var state = new ParserState();
	
				if ( text.indexOf( '\r\n' ) !== - 1 ) {
	
					// This is faster than String.split with regex that splits on both
					text = text.replace( /\r\n/g, '\n' );
	
				}
	
				if ( text.indexOf( '\\\n' ) !== - 1 ) {
	
					// join lines separated by a line continuation character (\)
					text = text.replace( /\\\n/g, '' );
	
				}
	
				var lines = text.split( '\n' );
				var line = '', lineFirstChar = '';
				var lineLength = 0;
				var result = [];
	
				// Faster to just trim left side of the line. Use if available.
				var trimLeft = ( typeof ''.trimLeft === 'function' );
	
				for ( var i = 0, l = lines.length; i < l; i ++ ) {
	
					line = lines[ i ];
	
					line = trimLeft ? line.trimLeft() : line.trim();
	
					lineLength = line.length;
	
					if ( lineLength === 0 ) continue;
	
					lineFirstChar = line.charAt( 0 );
	
					// @todo invoke passed in handler if any
					if ( lineFirstChar === '#' ) continue;
	
					if ( lineFirstChar === 'v' ) {
	
						var data = line.split( /\s+/ );
	
						switch ( data[ 0 ] ) {
	
							case 'v':
								state.vertices.push(
									parseFloat( data[ 1 ] ),
									parseFloat( data[ 2 ] ),
									parseFloat( data[ 3 ] )
								);
								if ( data.length === 8 ) {
	
									state.colors.push(
										parseFloat( data[ 4 ] ),
										parseFloat( data[ 5 ] ),
										parseFloat( data[ 6 ] )
	
									);
	
								}
								break;
							case 'vn':
								state.normals.push(
									parseFloat( data[ 1 ] ),
									parseFloat( data[ 2 ] ),
									parseFloat( data[ 3 ] )
								);
								break;
							case 'vt':
								state.uvs.push(
									parseFloat( data[ 1 ] ),
									parseFloat( data[ 2 ] )
								);
								break;
	
						}
	
					} else if ( lineFirstChar === 'f' ) {
	
						var lineData = line.substr( 1 ).trim();
						var vertexData = lineData.split( /\s+/ );
						var faceVertices = [];
	
						// Parse the face vertex data into an easy to work with format
	
						for ( var j = 0, jl = vertexData.length; j < jl; j ++ ) {
	
							var vertex = vertexData[ j ];
	
							if ( vertex.length > 0 ) {
	
								var vertexParts = vertex.split( '/' );
								faceVertices.push( vertexParts );
	
							}
	
						}
	
						// Draw an edge between the first vertex and all subsequent vertices to form an n-gon
	
						var v1 = faceVertices[ 0 ];
	
						for ( var j = 1, jl = faceVertices.length - 1; j < jl; j ++ ) {
	
							var v2 = faceVertices[ j ];
							var v3 = faceVertices[ j + 1 ];
	
							state.addFace(
								v1[ 0 ], v2[ 0 ], v3[ 0 ],
								v1[ 1 ], v2[ 1 ], v3[ 1 ],
								v1[ 2 ], v2[ 2 ], v3[ 2 ]
							);
	
						}
	
					} else if ( lineFirstChar === 'l' ) {
	
						var lineParts = line.substring( 1 ).trim().split( " " );
						var lineVertices = [], lineUVs = [];
	
						if ( line.indexOf( "/" ) === - 1 ) {
	
							lineVertices = lineParts;
	
						} else {
	
							for ( var li = 0, llen = lineParts.length; li < llen; li ++ ) {
	
								var parts = lineParts[ li ].split( "/" );
	
								if ( parts[ 0 ] !== "" ) lineVertices.push( parts[ 0 ] );
								if ( parts[ 1 ] !== "" ) lineUVs.push( parts[ 1 ] );
	
							}
	
						}
						state.addLineGeometry( lineVertices, lineUVs );
	
					} else if ( lineFirstChar === 'p' ) {
	
						var lineData = line.substr( 1 ).trim();
						var pointData = lineData.split( " " );
	
						state.addPointGeometry( pointData );
	
					} else if ( ( result = object_pattern.exec( line ) ) !== null ) {
	
						// o object_name
						// or
						// g group_name
	
						// WORKAROUND: https://bugs.chromium.org/p/v8/issues/detail?id=2869
						// var name = result[ 0 ].substr( 1 ).trim();
						var name = ( " " + result[ 0 ].substr( 1 ).trim() ).substr( 1 );
	
						state.startObject( name );
	
					} else if ( material_use_pattern.test( line ) ) {
	
						// material
	
						state.object.startMaterial( line.substring( 7 ).trim(), state.materialLibraries );
	
					} else if ( material_library_pattern.test( line ) ) {
	
						// mtl file
	
						state.materialLibraries.push( line.substring( 7 ).trim() );
	
					} else if ( lineFirstChar === 's' ) {
	
						result = line.split( ' ' );
	
						// smooth shading
	
						// @todo Handle files that have varying smooth values for a set of faces inside one geometry,
						// but does not define a usemtl for each face set.
						// This should be detected and a dummy material created (later MultiMaterial and geometry groups).
						// This requires some care to not create extra material on each smooth value for "normal" obj files.
						// where explicit usemtl defines geometry groups.
						// Example asset: examples/models/obj/cerberus/Cerberus.obj
	
						/*
						 * http://paulbourke.net/dataformats/obj/
						 * or
						 * http://www.cs.utah.edu/~boulos/cs3505/obj_spec.pdf
						 *
						 * From chapter "Grouping" Syntax explanation "s group_number":
						 * "group_number is the smoothing group number. To turn off smoothing groups, use a value of 0 or off.
						 * Polygonal elements use group numbers to put elements in different smoothing groups. For free-form
						 * surfaces, smoothing groups are either turned on or off; there is no difference between values greater
						 * than 0."
						 */
						if ( result.length > 1 ) {
	
							var value = result[ 1 ].trim().toLowerCase();
							state.object.smooth = ( value !== '0' && value !== 'off' );
	
						} else {
	
							// ZBrush can produce "s" lines #11707
							state.object.smooth = true;
	
						}
						var material = state.object.currentMaterial();
						if ( material ) material.smooth = state.object.smooth;
	
					} else {
	
						// Handle null terminated files without exception
						if ( line === '\0' ) continue;
	
						throw new Error( 'THREE.OBJLoader: Unexpected line: "' + line + '"' );
	
					}
	
				}
	
				state.finalize();
	
				var container = new THREE.Group();
				container.materialLibraries = [].concat( state.materialLibraries );
	
				for ( var i = 0, l = state.objects.length; i < l; i ++ ) {
	
					var object = state.objects[ i ];
					var geometry = object.geometry;
					var materials = object.materials;
					var isLine = ( geometry.type === 'Line' );
					var isPoints = ( geometry.type === 'Points' );
					var hasVertexColors = false;
	
					// Skip o/g line declarations that did not follow with any faces
					if ( geometry.vertices.length === 0 ) continue;
	
					var buffergeometry = new THREE.BufferGeometry();
	
					buffergeometry.addAttribute( 'position', new THREE.Float32BufferAttribute( geometry.vertices, 3 ) );
	
					if ( geometry.normals.length > 0 ) {
	
						buffergeometry.addAttribute( 'normal', new THREE.Float32BufferAttribute( geometry.normals, 3 ) );
	
					} else {
	
						buffergeometry.computeVertexNormals();
	
					}
	
					if ( geometry.colors.length > 0 ) {
	
						hasVertexColors = true;
						buffergeometry.addAttribute( 'color', new THREE.Float32BufferAttribute( geometry.colors, 3 ) );
	
					}
	
					if ( geometry.uvs.length > 0 ) {
	
						buffergeometry.addAttribute( 'uv', new THREE.Float32BufferAttribute( geometry.uvs, 2 ) );
	
					}
	
					// Create materials
	
					var createdMaterials = [];
	
					for ( var mi = 0, miLen = materials.length; mi < miLen; mi ++ ) {
	
						var sourceMaterial = materials[ mi ];
						var material = undefined;
	
						if ( this.materials !== null ) {
	
							material = this.materials.create( sourceMaterial.name );
	
							// mtl etc. loaders probably can't create line materials correctly, copy properties to a line material.
							if ( isLine && material && ! ( material instanceof THREE.LineBasicMaterial ) ) {
	
								var materialLine = new THREE.LineBasicMaterial();
								THREE.Material.prototype.copy.call( materialLine, material );
								materialLine.color.copy( material.color );
								materialLine.lights = false;
								material = materialLine;
	
							} else if ( isPoints && material && ! ( material instanceof THREE.PointsMaterial ) ) {
	
								var materialPoints = new THREE.PointsMaterial( { size: 10, sizeAttenuation: false } );
								THREE.Material.prototype.copy.call( materialPoints, material );
								materialPoints.color.copy( material.color );
								materialPoints.map = material.map;
								materialPoints.lights = false;
								material = materialPoints;
	
							}
	
						}
	
						if ( ! material ) {
	
							if ( isLine ) {
	
								material = new THREE.LineBasicMaterial();
	
							} else if ( isPoints ) {
	
								material = new THREE.PointsMaterial( { size: 1, sizeAttenuation: false } );
	
							} else {
	
								material = new THREE.MeshPhongMaterial();
	
							}
	
							material.name = sourceMaterial.name;
	
						}
	
						material.flatShading = sourceMaterial.smooth ? false : true;
						material.vertexColors = hasVertexColors ? THREE.VertexColors : THREE.NoColors;
	
						createdMaterials.push( material );
	
					}
	
					// Create mesh
	
					var mesh;
	
					if ( createdMaterials.length > 1 ) {
	
						for ( var mi = 0, miLen = materials.length; mi < miLen; mi ++ ) {
	
							var sourceMaterial = materials[ mi ];
							buffergeometry.addGroup( sourceMaterial.groupStart, sourceMaterial.groupCount, mi );
	
						}
	
						if ( isLine ) {
	
							mesh = new THREE.LineSegments( buffergeometry, createdMaterials );
	
						} else if ( isPoints ) {
	
							mesh = new THREE.Points( buffergeometry, createdMaterials );
	
						} else {
	
							mesh = new THREE.Mesh( buffergeometry, createdMaterials );
	
						}
	
					} else {
	
						if ( isLine ) {
	
							mesh = new THREE.LineSegments( buffergeometry, createdMaterials[ 0 ] );
	
						} else if ( isPoints ) {
	
							mesh = new THREE.Points( buffergeometry, createdMaterials[ 0 ] );
	
						} else {
	
							mesh = new THREE.Mesh( buffergeometry, createdMaterials[ 0 ] );
	
						}
	
					}
	
					mesh.name = object.name;
	
					container.add( mesh );
	
				}
	
				console.timeEnd( 'OBJLoader' );
	
				return container;
	
			}
	
		};
	
		return OBJLoader;
	
	} )();
}